The present invention relates generally to a tool for the automatic installation of a cable tie around a bundle of wires and, more specifically, to a guide channel for such a tool that improves cable tie feed to avoid cable tie jams resulting from bounce back.
A wide variety of cable tie application tools are known. Some provide individual cable ties from a remote dispenser having a cartridge or reel containing a large number of cable ties to a conveyance mechanism for provision to the application tool.
One special type of cable tie application tool has used the application of pressurized air to convey the individual cable ties from the dispenser to a hand manipulated application tool at very high rates of speed, propelling cable ties to a cable tie tool head at up to 50-80 MPH, for application to a bundle of wires. Examples include U.S. Pat. No. 3,946,769 to Caveney et al., U.S. Pat. No. 4,004,618 to Turek, U.S. Pat. No. 4,498,506 to Moody et al., and U.S. Pat. No. 5,722,466 to Levin et al. Tools based on these patents are also commercially available from Panduit Corporation and marketed under the tradenames PAT1M for use with cable bundles up to about 0.82″, PAT1.5M for bundles up to about 1.31″, and PAT2S for bundles up to 2″ in diameter.
These remote dispenser cable tie installation tools are very desirable and have been highly successful for situations where maximum volume and speed of application is necessary. However, due to the very high operating rates of speed, cable tie jams within the guide channel of the tool or incomplete cable tie attachment occasionally occur, which may result in extensive delays and repair costs that can be very significant. In particular, as the feed rates increase, forces acting on the fed cable tie as it is rapidly stopped by a head stop assembly can cause a tendency for the cable tie to “bounce back” in a rearward direction from the head stop assembly back towards the guide channel.
Certain existing models of cable tie application tools include a guide channel mechanism that assists travel of the cable tie through the channel and may resist some “bounce back.” The mechanism includes use of two biased side members or a single biased, pivotal lower guide surface. Examples of these are shown in U.S. Pat. No. 4,498,506 to Moody et al., U.S. Pat. No. 4,004,618 to Turek, and U.S. Pat. No. 5,845,681 to Kurmis. Such tools were intended for low dispense speeds. However, with certain tools requiring higher dispense feed rates, secure retention of the cable tie head becomes problematic because the biased guide members may not respond quick enough to fully prevent “bounce back.”